Polishing apparatus



C. A. ANDRYSICK ETAL July 23, 1957 POLISHING APPARATUS 2 Sheets-Sheet 1Filed May 14', 1954 Q INVENTORS (2 5mm 4. 10mm? vs: c-Ic BY AND M4 BEA?CP/QLMEA M ,7. 041

July 23, 1957 c. A. ANDRYSICK ETAL 2,799,974

POLISHING APPARATUS Filed May 14, 1954 2 Sheets-Sheet 2 Y Y 75 82 Y Y I532 CYL- A. CYL. v

x INVENTORS 5'? E 73 85 Y (#5575? 14. film 019x51 CK 1' na MLBER CP/ILMER X may ATTOR Y.

United POLISI-HN'G APPARATUS Chester A. Andrysick and Wilbur C. Palmer,Corning, N. Y., assiguors to Corning Glass Works, Corning, N. Y., acorporation of New York Application May 14, 1954, Serial No. 429,942

7 Claims. (Cl. 5155) The present invention relates to an apparatussuitable for use in polishing the relatively large surfaces of tools orwork-pieces employed in the formation of glass articles, such forexample as those used in the pressing of the viewing screens oftelevision picture tubes.

According to the invention facilities are provided for effecting backand forth movements between a work-piece and a rotating polishing headslidably engaged therewith to polish the work-piece surface between twooppositely disposed margins thereof. In the meantime similar transversemovements are effected back and forth between the polishing head and thework-piece to polish the workpiece surface between the remainingopposite margins thereof. Such latter movements are arranged to occur ata relatively slow rate of speed such that, for each first definedrelative movement between the head and the work-piece, the distance oftransverse movement amounts to less than the width of the polishinghead. The arrangement thus is such that for each first defined pass ormovement the head engages an area overlapping that engaged therebyduring the preceding similar pass. As will be understood the respectiveback and forth movements are continued until the polishing head hasimparted the desired surface quality to the work-piece.

In the accompanying drawings:

Fig. 1 is a top plan view of a preferred form of machine embodying theinvention having arranged thereon a workpiece comprising a televisionviewing screen forming mold.

Fig. 1a is an enlarged view taken on line 1a-1a of Fig. 1.

Fig. 2 is a side elevation of the machine showing certain parts thereofand the work-piece thereon in section.

Fig. 3 is an enlarged view, partly in section, of the polishing head anda portion of the spindle assembly of the machine.

Fig. 4 is an enlarged plan view of a fragment of a frame of electricalinsulating material, supported by the workpiece arranged on the machine,and carrying contacts co-operative with a contactor carried by thepolishing head spindle and employed in controlling the back and forthmovements between the polishing head and the workiece.

P Fig. 5 is an enlarged view taken on line 55 of Fig. 4; and also shows,in elevation, the polishing head and the lower portion of its supportingspindle assembly.

Fig. 6 is an enlarged view taken on line 6-6 of Fig.4.

Fig. 7 is a combined wiring and piping diagram of the machine, andincludes a sectional view of one of the valves employed in effecting theback and forth movements hereinfor referred to.

Referring to the machine in detail, it embodies a frame 11 the top ofwhich is employed as a track 12 for. a carriage 13 adapted to receive awork-piece such as mold 14. The carriage 13 is adapted to bereciprocated over track 12 by means of a fluid operated unit whosecylinder 15 is fixed to frame 11 and whose operating rod 16 is coupledto the carriage 13 through suitable cushioning springs 17.

The polishing head 21, shown in polishing engagement with the mold 14,is supported on a vertically disposed spindle assembly 22 mounted in asuitable bearing 20 carried on one end of a horizontal rod 23 runningparallel to the track 12 and at its other end secured to a bracket 24.Bracket 24 is provided with a motor 25 by means of which the polishinghead 21 is rotated through the medium of a belt 26. Bracket 24 ispivoted to a cap assembly 28 about a horizontal axis 27 extending normalto the rails of track 12. Assembly 28 in turn is pivotally supportedabout a vertical column 30. A horizontally disposed arm 31 is secured atone end to the side of assembly 28 (Fig. 1a) and at the other end isresiliently coupled through springs 17' (Fig. l) to the rod 32 of afluid operated unit whose cylinder 33 is pivoted at 34 to the frame 11.As will be seen therefore, by means of the unit embodying cylinder 33 itis possible to oscillate the polishing head 21 between the lateralmargins of the work-piece or mold 14. A weight 40, slidable along rod23, permits the pressure applied by the polishing head 21 to thework-piece to be suitably regulated to obtain the polishing actiondesired.

The supplying of fluid to the respective fluid operated unit cylinders15 and 33 as required to reciprocate carriage 13 and to oscillate thehead 21 is effected by means of conventional magnetically actuatedfour-way control valves 7 0 and 71 (Fig. 7) respectively, which areidentical in all respects. Valves and 71 are in turn adapted to becontrolled by a set of relays A to D whose respective operating circuitsinclude a contactor 35, carried by the bearing 2%) of the spindleassembly 22, and in contact such as 1, 2, 3 or 4 carried by a frame 61of electric insulating material arranged on the work-piece or mold 14.The lower side of frame 61 is provided with a number of blocks such as51 (Fig. 5) adapted to register with suitable notches such as 51 in thework-piece and thus hold the frame fixed with respect thereto during apolishing operation. Arranged on two of the oppositely disposed uppersurfaces of frame 61 are contacts 3 and 4 (Figs. 1, 4 and 7) which arefixed with respect to the frame. On each of the remaining two oppositelydisposed upper surfaces of frame 61 are plates hereinafter referred toas contacts 1 and 2, that extend the width of the work-piece surface tobe polished and are mounted for limited sliding movement under bracketssuch as 60 on the frame 61 in the directions of movement of carriage 13,but normally pulled toward one another by suitable springs such as 41.The contacts 1 and 2 have slotted ends such as 63, illustrated in Fig.6, which straddle aligning pins such as 64 passing through the bracket60 and frame 61. As will be more fully described hereinafter, contacts 1and 2 are engaged by contactor 35 through the movement of carriage 13and are included in the circuits of relays A and B, respectively,employed in the actuation of valve 70 to control the reciprocation ofthe carriage. Contacts 3 and 4 on the other hand are engaged bycontactor 35 through movement of head 21 and are included in thecircuits of relays C and D, respectively, employed in the actuation ofvalve 71 to control the oscillation of the head 21. Relays A and Bthrough the medium .of control valve 70 cause fluid to be supplied tocylinder 15 in the fashion necessary, as will become clear hereinafter,to effect the reciprocation of its rod 16. This results in thereciprocathe lateral margins of mold #14 with which contacts 3 and 4 areassociated. from a detailed description of the 'operations'oceurringunder control of relays C andD the operations that occur under'controlof relays-A and Bwill be;evident. 3 1

mold 14 as required to alter- -With relay C deenergized, as showiiitwill be observed that a closed circuit exists through the magnet 86'pfvalve -71 and that accordingly the spool of this valve has been moved toits leftward position. This circuit extends from aterminal X-of a;suitable current source, through the back contacts of relay C and thewinding to a Y terminal of the same current source. V V

- Op'erating'fluidis supplied to cylinders'15 and 33 from a suitableireservoir 69 by means ofa constant delivery pump 72 driven by'a'motor' 73. With the spool of valve -71 in the position shownjfluidfrom pump 72 passes through a check'valve 74, line 75, through valve 71,line 78, needle valve '79, and to the right end'of cylinder 33. Atth'esame time a path for the return of fluid from the 'left'end ofcylinder 33t0 the reservoir 69 extends via line 81, needle valve 82, thevalve '71 and line 83. The rod 32 is at the present time accordinglymoving in the direction indicated by the arrow. By reference to Fig. 1it will be seen that with the rodi32 moving into cylinder 33, asindicated in Fig. 7, the polishing head 21 will be moving towardcontact3. Therefore, ultimately, during one of the reciprocating movementsof'carriage 13 the contactor 35 will engage such contact. When contact 3is engaged by contactor 35 relay'C becomes energized over a circuitextending from the terminal X of a suitable current source, through thewinding of relay C, contact 3, contactor 35 and a Y terminal of the samesource. Relay C, upon becoming energized, at its innermost contacts 66,completes a locking circuit for itself including a conductor 67 and thebreak contacts 68 of'relay D, at its outer break contact 69, interruptsthe circuit through magnet 86 and at its outer front contact 76completes a circuit for magnet 87. As a result of the completion of thilatter circuit, thespool ofmagnet 71 is moved to the right, therebyreversing the fluid connections to cylinder 33 to efifect a reversal indirection of movement of rod 32 and a consequent reversal in directionof movement of the polishing head 21. As will be quite obvious, at suchtime that the contactor 35 engages contact 4 relay D will becomeenergized and thus break the locking circuit of relay C so that it willrestore and thus reestablish the set of conditions prevailing at theoutset of the description. As will be understood the needle valves 79and 82, included in the fluid lines 78 and 81 between valve 71 andcylinder 33, are provided for the purpose of slowing up the transversemovement of head 21 to the extent required to assure that for eachrelative movement between the polishing head and those margins of themold with which contacts 1 and 2 are associated, the distance oftransverse movement of the polishing head will be less than the diameterof its polishing surface, so that overlapping of the preceding engagedsurface will be assured.

, Itrwill be observed that with relay A deenergized the magnet winding90 of valve 70 is' presently energized and that, accordingly, the spoolof such valve is occupying its rightward position, as indicated.Therefore, at the present time fluid is beingsupplied to the left end ofcylinder 15 through line 76 and, accordingly, rod 16 and the carriage 13connected thereto are moving to the right.

4 der 15 following the engagement by contactor 35. V

In order to protect the operating mechanism should a reversal indirection of movement of either the head 21 or of the mold carriage 13fail to occur when intended, the operating circuits of the motors 25 and73 are passed of one of such contacts through the break contacts of arelay E. Relay E in turn has alternate operating circuits closeable bycontacts 88 adapted to be operated by rod 16 in either direction of itsmovement and similar operating circuits closeable by contacts 93 adaptedto be operated by rod 32, should either of such rods fail to reverse itsdirection of movement substantially immediately after the contactorengages its controlling contact carried by frame 61.

Although the invention has been disclosed with the form of work-piecesupport carriage and contact carrying frame that are most suitable forthe particular work-piece shown, it will be understood that the form ofwork-piece support and of the contact carrying frame are whollydetermined by the shape of the particular work-piece to be polished. Itwill be obvious, therefore, that variations of the invention necessaryfor the polishing of work-pieces of other forms may be made within thescope and spirit of the appended claims.

What is claimed is:'

1. In a polishing machine, a length of track, a workpiece supportcarriage arranged on said track, a rotatable Contacts 1 and 2 are madeslidable to permit a limited I polishing head arranged over saidcarriage and adapted to engage the surface of a work-piece thereon to bepolished, means for moving said carriage back and forth along said trackto progressively associate said head with different surface areas of thework-piece, means for mov-. 7

ing said polishing head back and forth transversely of the track toprogressively associate said head withother surface areas of suchwork-piece, electric control circuits for both of said means, and acontactor common to said circuits for closing one of said circuitsconsequent to the arrival of, the work-piece at either of alternatepredetermined positions along the track and upon the arrival of the headat either of alternate predetermined lateral positions with respect tothe work-piece to reverse the direction of movement of the carriage orof the head as the case may be. p

2. A polishing machine such as defined by claim 1, wherein said electriccircuits each include said contactor and a diflerent companion electriccontact element arranged in the vicinity of each one of suchpredetermined positions.

3. A polishing machine such as defined by claim 2 wherein said contactelements are carried by a frame supported on the work-piece.

4. A polishing machine such as defined by claim 3 wherein a spring isarranged between said frame and at least one of said contact elements toimpart a resilient yielding character thereto when engaged by saidcontactor. f

5. In a polishing machine a length of track, a work- .piece supportcarriage arranged on said track, a rotatable polishing head arrangedover said carriageand adapted to engage the surface of a work-piecethereon to be polished, means for moving said carriage back and forthalong said track to progressively associate said head with differentsurface areas of the work-piece, means for moving said polishing headback and forth transversely of the track to progressively associate saidhead with other surface areas of such work-piece, relays under whosecontrol the respective back and forth movements are effected, a frameadapted to be carried by the work-piece having contacts bordering theboundary of the region of the work-piece to be polished included in therespective circuits of said relays, and a contact element carried'by thepolishing head spindle included in the circuit of each 6. A machine suchas defined by claim 1 wherein each of said control circuits includes adifferent relay.

7. A machine such as definrd by claim 6 wherein magnetic valves foreffecting such reversals are under the selective control of said relays.5

References Cited in the file of this patent UNITED STATES PATENTS1,180,260 Grice Apr. 18, 1916 10 1,783,960 Fox Dec. 9, 1930 1,927,007Whittles Sept. 12, 1933 6 Brown May 22, 1934 Shaw Feb. 8, 1938 NenningerMar. 15, 1938 Baldenhofer Apr. 5, 1938 Wortondyke Jan. 23, 1945 FOREIGNPATENTS Germany Feb. 18, 1904 Great Britain Dec. 3, 1929 Great BritainMay 19, 1930

